By 2050, four million people and around 70 per cent of today's Arctic infrastructure, will be threatened by thawing permafrost.

From 1979 to the present, Arctic sea ice is estimated to have declined by 40 per cent.

Nairobi:

Even if the world were to cut emissions in line with the 2015 Paris Climate Change Agreement, winter temperatures in the Arctic would rise three to five degrees Celsius by 2050 and five to nine degrees by 2080, devastating the region and unleashing sea level rises worldwide, a new report by the UN Environment warned on Thursday.

Rapidly thawing permafrost could even accelerate climate change further and derail efforts to meet the Paris Agreement's long-term goal of limiting the rise in global temperature to two degrees Celsius, warns the report titled "Global Linkages -- A graphic look at the changing Arctic".

By 2050, four million people and around 70 per cent of today's Arctic infrastructure, will be threatened by thawing permafrost.

Other environmental pressures on the Arctic identified by the paper, released at the ongoing United Nations Environment Assembly in Nairobi that will conclude on Friday, include ocean acidification and plastic pollution.

"What happens in the Arctic does not stay in the Arctic," UN Environment's Acting Executive Director Joyce Msuya said.

"We have the science; now more urgent climate action is needed to steer away from tipping points that could be even worse for our planet than we first thought."

Even if global emissions were to halt overnight, winter temperatures in the Arctic would still increase four to five degrees Celsius by 2100 compared to the late 20th century, the study said.

This increase is locked into the climate system by greenhouse gases already emitted and ocean heat storage.

"The urgency to achieve the goals of the Paris Agreement is clearly manifested in the Arctic, because it is one of the most vulnerable and rapidly changing regions in the world," Finnish Environment Minister Kimmo Tiilikainen said in a statement.

"We need to make substantial near-term cuts in greenhouse gas emissions, black carbon and other so-called short-lived climate pollutants all over the world."

The impacts globally would also be huge.

From 1979 to the present, Arctic sea ice is estimated to have declined by 40 per cent.

Climate models predict that, at the current rate of carbon dioxide emissions, Arctic summers will be ice-free by the 2030s.

The melting of the Greenland ice cap and Arctic glaciers contribute to one-third of sea level rise worldwide.

Even if the Paris Agreement is met, Arctic permafrost is expected to shrink 45 per cent compared to today.